Radio receiving apparatus



May 3, 1932. B. P. HAMILTON ET AL RADIO RECEIVING APPARATUS Filed July 2, 1929 mm/E ATTORNEY A INVENTORS lgYQ/m miauw w Patented May 3, 1932 UNITED ,STATES PATENT OFFICE BAXTER P. HAMILTON, OF RIVER EDGE, NEW JERSEY, AND WILTON T. REA, OF FLUSH- TNG, NEW YORK, ASSIGNGBEJ 130 AMERCAN TELEPHONE AND TELEGRAPH COM- IPANY, A CORPGRATION 0F NEW YORK RADIO RECEIVING APPARATUS Application led July 2, 1929. Serial No. 375,380.

This invention relates to transmission systems over which a plurality ot ditlerent carrier channels may be transmitted, and more particularly relates to improved arrange ments whereby receivingl or translating ap paratus in such systems may be controlled so as to be rendered selective for any one oi the transmitted carrier channels.

@ne of the purposes ot the arrangements of the invention is to make it possible to accurately tune a radio receiving set to different transmitting stations by means oi simple switches or push buttons which may be located either atthe set or at certain control points at some distance from the radio set. rlllie arrangements of the invention might also be utilized to control apparatus other` than a radio receiving set. For example, the arrangements might control repeater apparatus in a carrier 'transmission system so that it could be timed automatically at a distance 'for the various carrier channels. The arrangements of the invention also provide further features, such as remote control of vol- Lune, means for switching the control appa- 1atus on and oli" from distant control points, and means for preventing the switching operations from causing disturbing noises in the apparatus. Further objects and teatures of the invention will appear more fully troni the detailed description thereof here inaiter given.

The invention may be more fully understood from the following description together with the accompanying drawing, in the ligure of which is shown a circuit diagram embodyingr the invention.

In the drawing, the arrangements of the invention are shown as adapted to control the tuning and other features of a radio receiving set. The radio receiving' set coinprises an antenna circuit 1 connected to a radio amplifier tube 2. This tube is connected to a detector tube 3. The detector tube is connected to the audio amplifiers l and 5, which in turn are connected to an output circuit 6. In order to control selectivity and volume of the radio receiving set, a nu1nher of switches are provided at different control points either at the receiving set, or distant therefrom, or both. Such points are shown as A and B. The switches 7 and 8 are located at point A, and the switches 9 and 10 are located at point B. The tuning ot the 'adio receiving,l set may be controlled in a Welldmovvn manner by connecting, across the input circuits oi the radio ampliiier tube 2 and the detector tube 3, condensers of dilierent values. Accordingly, there is shown associated with the input circuit oi' the radio ampliiier 2 a plurality of condenser circuits, such as 11, 13, 15 and 17. There is shown associated with the input circuit of the detector tube 3 the condenser circuits 12, 11i, 16 and 18. The connection of any of these condenser arrangements across the input ot either tube i). or tube 3 is controlled by the relay arrangement comprising relays X1, X2, and X, and relays Y1, Y2, YS and L .A plurality of resistance elements, such as R1, R2, R3 and RAL, are shown connected to the antenna circuit 1. Various ones of these resistance. elements may be connected to ground by the above-mentioned series of X relays, and hence the volume of incoming currents may be controlled. The condenser units 11 and 12 may each consist of a small liXed condenser and an adjustable air condenser ot small capacity. The condenser units 13, 14, 15 and 16 may be of a similar variety. The condenser units 17 and 18 are variable air condensers, of sufcient 'capacity to cover the entire range of frequencies desired. Condenser units 11 and 1:2 may be tuned for the reception of a channel from station 1, units 13and 14, for a channel from station 2, and units 15 and 16, for a channel from station 3. Units 17 and 18 may be adjusted for the reception of a channel vfrom station 4. The series of X relays and the series of Y relays are controlled by a relav arrangement comprising` the relays R, S, T, W and Z. These relays are under the control of the switches at the control points A and B. A pilot light indicator 19 is shown having individual lights tor each oit' the stat-ions to be received and is under the control of the series of Y relays.

The operation of the arrangements is as 1. of the series Y relays.

follows: It the switch 8 at the control point A is operated, a circuit will be completed trom ground contact of key 8, winding of relay T to battery 2O and ground. This will operate the relay T and the following circuit will be completed: From battery 20, right-hand inner contact of relay l/V, contact of relay T, lett-hand contact of relay lV, winding of relay Z to ground. This will operate the relay Z. The operation oi relay Z will connect battery 20 to conductor Q1 and thence to the iilaments of all of the tubes in the set. lt will also connect battery 2O over conductors 2l and 22' to one terminal of all It will also connect ground to the right-hand contact of relay Z and thence over conductor 23 to the winding of relay Y1. This will operate relay Y1. The switch 8 will then be released. The release or switchy 8 will release the relay T. The release ot relay T will remove an effective short-circuit from the winding ot relay lV. This allo-ws relays W and Z to lock in the operated position with their windings in series with the battery 20. 'Vhen relay lV operates, it removes the ground connected over its outer right-hand contact and conductor 23 to the connection beween relays X1 and Y1. This will allow the operating circuit of relay Y1 to be completed through the winding ot relay X1, lower contact of relay Y1 and over the upper contact of relay i 2 to ground, thereby operating relay X1. Relays X1 and Y1 will then remain in operated condition. Thus, one operation and release of the switch 8 closes the lilament circuits for all the tubes and locks the pair of relays X1 and Y1 corresponding to station l in the operated position. The operation of relays X1 and 4Y1 will remove short circuits about the condenser units ll and l2 and allow said units to be connected, respectively, across the input circuits of the radio amplifier 2 and the detector 3, thereby tuning the set for reception of signals from station A. The operation of relay X1 will also connect resistance R1 between the antenna circuit 1 and ground. This will regulate the volume for the channel to be received from station A. The operation ot relay Y1 will also close a circuit for one of the lamps in the pilot light indicator 19 to indicate that the arrangements have been tuned for reception from station l.

' It the key 7 at station A is now operated, the relays R and S will be operated. The

operation of relay R will connect ground over conductor 24, lower contact of relay X1 to the connection between relays X2 and Y2.

This will complete a circuit from battery 2O for the relay Y2 and allow it to operate. The

Yrelease of key 7 will then remove a short circuit to ground from the winding of relay X2 and allow the operating circuit of Y2 to be completed through the winding oi"- relay X2, overv the lower contact of relay Y2 and over set will be tuned for reception of signals from station 2. Subsequent operation of switch 7 will lock up the further X and Y relays in rotation and tune the receiving set for reception to other stations. The next operation of switch 8 will again operate relay lT and connect a short-circuit to the winding of the previously operated relay WV. This will allow relay W to release. The subsequent release of the switch 8 will release the relay T, and hence release the relay Z. Accordingly, all of the relays in the system will be returned to normal.

Relays R and S, and the right armature of relay T, have been provided to eliminate clicks in the output circuit while switching between stations, due, among other factors, to sparking of the relay contacts and the pilot light and pilot light indicators. There is a disagreeable click when the switch 7 is operated, when the switch 7 is released, and when the switch 8 is operated to the off position; that is, when battery is removed from the tubes and relays. Accordingly, theright contacts of relays R, S and T have been connected in series with the input circuit of the power ampliiier 5. This input circuit may be opened at these points without causing aclick in the loud speaker' which mi ght be connected to the output circuit 6. VJ hen the switch 7 is operated, relay R operates first and disconnects the last audio amplifier 5 and loud speaker. The relay S, which is comparatively' slow-acting and slow-release, is also operated. l/Vhen the switch 7 is released, re-

lay R releases, and, at a later interval, relay S releases, thus connecting the audio amplifier tube to the other tubes after all switching disturbances have ceased. Similarly, when turning otl the set by the operation of switch 8, relay T is the irst to operate. This disconnects the audioamplifier tube 5 while relay Z is releasing, and eliminates any tendency for noise.

lVhile the invention has been disclosed as embodied in certain specific arrangements which are deemed desirable, it is understood that it is capable of embodiment in many and other widely varied forms without departing from the spirit of the invention as delined by the appended claims.

`What is claimed is: Y

l. Apparatus for translating a plurality of different carrier channels, an input circuit connected to said translating apparatus, a plurality of selective circuits for tuning said input circuit for a desired one ot said carrier channels, a series of progressively operated relays for progressively connecting said selective circuits to said input circuit, different volume adjusting means adapted to be con 5 nected to said input circuit by said series of relays, and switching means for starting the progressive operation of said series of relays,

Vtor stopping said operation and for restoring saidL relays to normal. l0 2. Apparatus for translating a plurality of different carrier channels, an input circuit connected to said translating apparatus, a plurality of circuits for selectively tuning said input circuit for said different carrier channels, a plurality of volume adjusting eleinents one corresponding to each tuning circuit, a series of relays for operating said sei lective tuning circuits and said volume adjusting elements, a control circuit for said series of relays, and additional progressively operated relays in said control circuit for disabling said translating means during the opation of said series of relays.

3. A high frequency carrier receiving sys teni comprising vacuum tube amplifying, detecting and receiving apparatus, an input cir cuit for said apparatus, a plurality of condenser units of diferent capacity each adapted to be bridged across said input circuit, a 30 series of progressively operated relay means, each of the relays thereof being adapted to bridge one of said condenser units across said input circuit, a control circuit for said relays, means in said control circuit responsive to "i3 the closure thereof for temporarily disabling said receiving apparatus, and additional means in said control circuit responsive to a subsequent closure thereof for again temporarily disabling said receiving apparatus.

ln testimony whereof, We have signed our naines to this specification this 1st day of July, 1929.

BAXTER P. HAMILTON. VVILTON T. REA. 

